Bicycle hydraulic operating device

ABSTRACT

A bicycle hydraulic operating device is basically provided with a base member, a piston, an operating member and a hydraulic reservoir. The base member includes a cylinder bore. The piston is movably disposed in the cylinder bore. The operating member is coupled to the piston to move the piston within the cylinder bore. The hydraulic reservoir includes a hydraulic reservoir tank and a reservoir lid. The hydraulic reservoir is provided on the base member and is fluidly connected to the cylinder bore by a fluid passage. At least part of one of the base member and the hydraulic reservoir includes a fluid inspection portion making visually perceptible therethrough at least a portion of a hydraulic fluid flow path that includes the hydraulic reservoir, the cylinder bore and the fluid passage.

BACKGROUND Field of the Invention

This invention generally relates to a bicycle hydraulic operatingdevice. More specifically, the present invention relates to a bicyclehydraulic operating device for operating a hydraulically actuatedcomponent of a bicycle.

Background Information

Bicycle hydraulic brake systems are typically actuated by a hydraulicbrake operating device. The hydraulic brake operating device typicallyincludes a master piston that is slidably disposed in a cylinder bore ofa master cylinder, and a brake lever actuating the master piston. Themaster cylinder contains a hydraulic fluid. The cylinder bore of themaster cylinder is in fluid communication with a disc brake caliperhousing in the case of a hydraulic disc brake via a fluid conduit. Brakepads of the disc brake caliper housing are typically spaced apart from arotor by a predetermined gap. The movement of fluid into the caliperhousing causes the pistons in the caliper housing to move, andeventually brings the brake pads into contact with a rotor.

SUMMARY

Generally, the present disclosure is directed to various features of abicycle hydraulic operating device.

In view of the state of the known technology and in accordance with afirst aspect of the present disclosure, a bicycle hydraulic operatingdevice is basically provided that comprises a base member, a piston, anoperating member and a hydraulic reservoir. The base member includes acylinder bore. The piston is movably disposed in the cylinder bore. Theoperating member coupled to the piston to move the piston within thecylinder bore. The hydraulic reservoir is provided on the base memberand is fluidly connected to the cylinder bore by a fluid passage. Atleast part of one of the base member and the hydraulic reservoirincludes a fluid inspection portion making visually perceptibletherethrough at least a portion of a hydraulic fluid flow path thatincludes the hydraulic reservoir, the cylinder bore and the fluidpassage. According to the first aspect of the present invention, thebicycle hydraulic operating device is configured so that a state of thehydraulic fluid in the hydraulic fluid flow path of the hydraulicoperating device is easily confirmed.

In accordance with a second aspect of the present invention, the bicyclehydraulic operating device according to the first aspect is configuredso that the hydraulic reservoir includes a hydraulic reservoir tankprovided on the base member, a reservoir lid closing a tank opening ofthe hydraulic reservoir tank and a diaphragm that is at least partiallydisposed inside the hydraulic reservoir tank. According to the secondaspect of the present invention, the state of the hydraulic fluid isconfirmed without disassembling the reservoir lid and the diaphragm.

In accordance with a third aspect of the present invention, the bicyclehydraulic operating device according to the second aspect is configuredso that the hydraulic reservoir tank and the base member are made of aresin material. According to the third aspect of the present invention,the bicycle hydraulic operating device is configured such that the basemember and the reservoir tank are easily provided as lightweightportions for reducing an overall weight of the bicycle hydraulicoperating device.

In accordance with a fourth aspect of the present invention, the bicyclehydraulic operating device according to the second or third aspect isconfigured so that the reservoir lid is made of a resin material.According to the fourth aspect of the present invention, the bicyclehydraulic operating device is configured such that the reservoir lid iseasily provided as lightweight portion for reducing an overall weight ofthe bicycle hydraulic operating device.

In accordance with a fifth aspect of the present invention, the bicyclehydraulic operating device according to any one of the second to fourthaspects is configured so that the fluid inspection portion is disposedon at least one of the hydraulic reservoir tank, the reservoir lid andthe diaphragm. In general, there is tendency that air in the hydraulicfluid flow path is gathered to the hydraulic reservoir. According to thefifth aspect of the present invention, the state of the hydraulic fluidin the hydraulic fluid flow path is more easily confirmed.

In accordance with a sixth aspect of the present invention, the bicyclehydraulic operating device according to any one of the second to fifthaspects is configured so that the hydraulic reservoir tank is bonded tothe base member. According to the sixth aspect of the present invention,the bicycle hydraulic operating device is configured such that thereservoir tank is easily provided on the base member.

In accordance with a seventh aspect of the present invention, thebicycle hydraulic operating device according to any one of the second tosixth aspects is configured so that the hydraulic reservoir tank isfixed to the base member by a fastenerless joint. According to thetwelfth aspect of the present invention, the bicycle hydraulic operatingdevice is configured such that the reservoir tank is more easilyprovided on the base member.

In accordance with an eighth aspect of the present invention, thebicycle hydraulic operating device according to any one of the first toseventh aspects further comprises a bleed port fluidly connected to thehydraulic fluid flow path. According to the eighth aspect of the presentinvention, a bleeding process is started after confirming the state ofthe hydraulic fluid in the hydraulic fluid flow path.

In accordance with a ninth aspect of the present invention, the bicyclehydraulic operating device according to the eighth aspect is configuredso that the bleed port is disposed on the hydraulic reservoir. Ingeneral, there is tendency that air in the hydraulic fluid flow path isgathered to the hydraulic reservoir. According to the ninth aspect ofthe present invention, the bleeding process becomes easy.

In accordance with a tenth aspect of the present invention, the bicyclehydraulic operating device according to any one of the first to ninthaspects further comprises a handlebar mounting structure disposed on thebase member. According to the fourteenth aspect of the presentinvention, the bicycle hydraulic operating device is configured suchthat the base member can be effectively located for easy use by a rider.

In accordance with an eleventh aspect of the present invention, thebicycle hydraulic operating device according to any one of the first totenth aspects is configured so that the operating member includes alever pivotally mounted relative to the base member. According to thefifteenth aspect of the present invention, the operating member isconfigured as a lever so that the operating member can be easilyoperated by a rider.

In accordance with a twelfth aspect of the present invention, thebicycle hydraulic operating device according to any one of the first toeleventh aspects is configured so that the base member is configured tobe gripped by a user. An inner space of the base member is limited andthe hydraulic fluid flow path becomes complicated since the base memberis configured to be gripped by a user. According to the twelfth aspectof the present invention, the bicycle hydraulic operating device isconfigured such that the state of the hydraulic fluid is effectivelyconfirmed even in such the hydraulic fluid flow path.

In accordance with a thirteenth aspect of the present invention, thebicycle hydraulic operating device according to the twelfth aspect isconfigured so that the base member includes a handlebar receiving recessarranged at a first end portion and a pommel portion arranged at asecond end portion opposite to the first end portion. According to thethirteenth aspect of the present invention, the bicycle hydraulicoperating device is configured such that the base member can beeffectively located for easy use by a rider.

In accordance with a fourteenth aspect of the present invention, thebicycle hydraulic operating device according to the thirteenth aspect isconfigured so that the hydraulic reservoir tank at least partially formsthe pommel portion. According to the fourteenth aspect of the presentinvention, the bicycle hydraulic operating device is configured suchthat the pommel portion of the base member is used effectively.

In accordance with a fifteenth aspect of the present invention, thebicycle hydraulic operating device according to any one of the first tofourteenth aspects further comprises a shifting unit disposed on one ofthe base member and the operating member. According to the fifteenthaspect of the present invention, the bicycle hydraulic operating deviceis configured to be used to perform a shifting function in addition tothe braking function.

In accordance with a sixteenth aspect of the present invention, thebicycle hydraulic operating device according to any one of the first tofifteenth aspects further comprises a cover removably and reattachablydisposed on the base member and at least overlying the fluid inspectionportion. According to the sixteenth aspect of the present invention, thebicycle hydraulic operating device is configured to improve usercomfort.

In accordance with a seventeenth aspect of the present invention, thebicycle hydraulic operating device according to the sixteenth aspect isconfigured so that the cover is configured to at least visually coverthe fluid inspection portion. According to the seventeenth aspect of thepresent invention, the bicycle hydraulic operating device is configuredto hidden the fluid inspection portion.

In accordance with an eighteenth aspect of the present invention, thebicycle hydraulic operating device according to the sixteenth aspect isconfigured so that the cover is made of a rubber material. According tothe sixteenth aspect of the present invention, the bicycle hydraulicoperating device is configured to improve user comfort more effectively.

Also other objects, features, aspects and advantages of the disclosedbicycle hydraulic operating device will become apparent to those skilledin the art from the following detailed description, which, taken inconjunction with the annexed drawings, discloses one embodiment of thebicycle hydraulic operating device.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is an outside elevational view of a portion of a bicycle equippedwith a bicycle hydraulic operating device in accordance a firstillustrated embodiment in which the bicycle operating device is coupledto a drop handlebar in an installed position;

FIG. 2 is an outside devotional view, similar to FIG. 1, the bicyclehydraulic operating device coupled to the drop handlebar with the coverpulled back to expose inspection portions of a base member and ahydraulic reservoir;

FIG. 3 is a longitudinal cross sectional view of the bicycle hydraulicoperating device illustrated in FIGS. 1 and 2 with operating members intheir rest positions (non-operated position);

FIG. 4 is an enlarged, partial cross sectional view of a portion of thebicycle hydraulic operating device illustrated in FIGS. 1 and 2;

FIG. 5 is an enlarged, partial transverse cross sectional view of aportion of the bicycle hydraulic operating device illustrated in FIGS. 1to 3 as seen along section line 5-5 of FIG. 4;

FIG. 6 is a perspective view of selected parts of the bicycle hydraulicoperating device illustrated in FIGS. 1 to 4; and

FIG. 7 is an outside elevational view of a portion of a bicycle equippedwith a bicycle hydraulic operating device in accordance a secondembodiment in which the bicycle operating device is coupled to a drophandlebar in an installed position.

DETAILED DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the bicycle field fromthis disclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

Referring initially to FIGS. 1 and 2, a bicycle 10 is illustrated thatis equipped with a bicycle hydraulic operating device 12 in accordancewith a first embodiment. the bicycle hydraulic operating device 12 is aright hand side control device operated by the rider's right hand tooperate a first brake device (not shown) and a first gear shiftingdevice (not shown, e.g., an electric rear derailleur). It will beapparent to those skilled in the bicycle field that the configuration ofthe bicycle hydraulic operating device 12 can be adapted to a left handside control device that is operated by the rider's left hand.

As seen in FIGS. 1 and 2, the bicycle hydraulic operating device 12 ismounted a drop handlebar 14. In particular, the bicycle hydraulicoperating device 12 is mounted to a curved section 14 a of the drophandlebar 14. In other words, the bicycle hydraulic operating device 12is particularly designed for a bicycle that is equipped with the drophandlebar 12. As explained below, the bicycle hydraulic operating device12 includes both a braking function and a shifting function in a singleunit. However, it will be apparent to those skilled in the bicycle fieldfrom this disclosure that the shifting function could be eliminated fromthe bicycle hydraulic operating device 12 if needed and/or desired. Thebicycle hydraulic operating device 12 is a bicycle hydraulic brakeoperating device that is specifically designed to be mounted to thecurved section 12 a of the drop handlebar 12.

In the first embodiment, the bicycle hydraulic operating device 12 is abicycle brake/shift device, which is also known as a bicycle brifter. Abicycle brifter is a device that includes both a braking function and ashifting function in a single unit that is mounted to the bicycle. Abicycle dropdown brifter is a device that is specifically configured tobe mounted to the curved section 14 a of the drop handlebar 14, asillustrated in FIG. 1, and that includes both braking and shiftingfunctions in a single unit.

As illustrated in FIG. 2, the bicycle hydraulic operating device 12basically comprise a base member 20, a piston 22, an operating member 24and a hydraulic reservoir 26. In the first embodiment, the piston 22 andthe operating member 24 are configured as a piston pull-type hydraulicactuator. The bicycle hydraulic operating device 12 further comprises ahandlebar mounting structure 28 that is disposed on the base member 20.Preferably, the bicycle hydraulic operating device 12 further comprisesa shifting unit 30 that is disposed on one of the base member 20 and theoperating member 24. In the first embodiment, the shifting unit 30 isdisposed on the operating member 24.

As explained below, various parts of the bicycle hydraulic operatingdevice 12 are made of a material that makes a hydraulic fluid flow pathfrom the hydraulic reservoir 26 to a hydraulic cylinder chamber of thepiston visually perceptible to a user without special tools. Thus, forexample, various parts of the bicycle hydraulic operating device 12 aremade of a transparent or translucent material such that the hydraulicfluid flow path is visually perceptible to a user without special toolstherethrough transparent or translucent material. These various parts ofthe bicycle hydraulic operating device 12 in which the hydraulic fluidflow path is visually perceptible to a user without special toolsconstitute a fluid inspection portion of the bicycle hydraulic operatingdevice 12.

As illustrated in FIG. 3, the base member 20 includes a handlebarreceiving recess 32 and a pommel portion 34. The handlebar receivingrecess 32 is arranged at a first end portion 36. The pommel portion 34is arranged at a second end portion 38 that is opposite to the first endportion 36. The hydraulic reservoir 26 is provided on the base member 20to form at least a part of the pommel portion 34. The hydraulicreservoir 26 is provided on the second end portion 38 of the base member20 to form at least a part of the pommel portion 34. The base member 20defines a drop handlebar bracket, which is made of a suitable rigid,hard material such as a hard plastic material (e.g., resin), a fiberreinforced plastic material (e.g., resin), a metallic material, etc. Thebase member 20 is configured to be gripped by a user. Thus, the basemember 20 includes a grip portion 40 that is located at a middle portionof the drop handlebar bracket. In this first embodiment, the base member20 essentially consists of a one-piece, unitary member. Of course, thebase member 20 can include removable panels as needed and/or desired.

The handlebar mounting structure 28 is attached to the base member 20 atthe handlebar receiving recess 32. The handlebar mounting structure 28and the handlebar receiving recess 32 cooperate together to non-movablyattach the base member 20 to the curved section 14 a of the drophandlebar 14. In other words, the handlebar mounting structure 28 is aconventional handlebar clamp that is attached to the base member 20 forreleasably securing the base member 20 to the curved section 14 a of thedrop handlebar 14. The handlebar mounting structure 28 basicallyincludes a clamping band 28 a (i.e., a handlebar clamping member) and afirst fastener part 28 b (nut) that screws unto a second fastener part28 c (bolt) of the clamping band 28 a. The first and second fastenerparts 28 b and 28 c are located in a hole 40 a of the grip portion 40.In this way, in this first embodiment, the handlebar mounting structure28 is disposed on the base member 20. With the handlebar mountingstructure 28, a head of the first fastener part 28 b applies a firstforce on the base member 20 and a head of the second fastener part 28 capplies a second force on the clamping band 28 a when the handlebarmounting structure 28 is tightened to secure the base member 20 to thecurved section 14 a of the drop handlebar 14. By tightening the firstfastener part 28 b, the clamping band 28 a is moved toward the basemember 20 such that the curved section 14 a of the drop handlebar 14 issqueezed between the clamping band 28 a and the base member 20. It willbe apparent to those skilled in the bicycle field that the handlebarmounting structure 28 that is not limited to the illustrated clamp, butrather other suitable attachment mechanisms can be used as needed and/ordesired. In any case, the handlebar mounting structure 28 is mounted onthe base member 20 in the first embodiment.

As illustrated in FIGS. 1 and 2, the bicycle hydraulic operating device12 further comprises a cover 42 that is stretched over at least the gripportion 40 and the pommel portion 34, which includes the hydraulicreservoir 26, to provide a cushion to the grip portion 40 of the basemember 20 and to provide an attractive appearance. The cover 42 isconfigured to at least visually cover the fluid inspection portion.Accordingly, the shape of the cover 42 depends on which parts of thebicycle hydraulic operating device 12 forms the fluid inspectionportion. The cover 42 is removably and reattachably disposed on the basemember 20 and at least overlying the fluid inspection portion. In thisway, the fluid inspection portion can be easily exposed for inspectingthe hydraulic fluid flow path of the bicycle hydraulic operating device12. Typically, the cover 42 is made of elastic material such as rubber.In the illustrated configuration, the cover 42 is also often referred toas a grip cover.

The base member 20 includes a cylinder bore 44. The piston 22 is movablydisposed in the cylinder bore 44. The piston 22 and the internal surfaceof the cylinder bore 44 define a hydraulic cylinder chamber. Asillustrated in FIG. 2, the cylinder bore 44 is directly formed by thebase member 20. The cylinder bore 44 can be formed, for example, bycutting the bracket 12 or die molding of the base member 20. Thecylinder bore 44 is formed in a cylindrical shape. However, it will beapparent from this disclosure that an insert can be provided to the basemember 20 to form the cylinder bore 44. A hydraulic hose connector 46 isscrewed into the base member 20 to fluidly connect a hydraulic hose H toa hydraulic fluid channel (not shown) that connects the hose connector46 to an outlet port 48 of the hydraulic cylinder chamber. The cylinderbore 44 also has an inlet port 50 that is fluidly connected to thehydraulic reservoir 26 by a fluid passage 52. Thus, the hydraulicreservoir 26 is provided on the base member 20, and is fluidly connectedto the cylinder bore 44 by the fluid passage 52.

The operating member 24 is coupled to the piston 22 to move the piston22 within the cylinder bore 44. Thus, the piston 22 moves in thecylinder bore 44 in a reciprocal manner in response to operation of theoperating member 24. In particular, the piston 48 moves linearly withinthe cylinder bore 44 (i.e., reciprocates linearly within the cylinderbore 44) to force the hydraulic fluid out of the outlet port 48 of thehydraulic chamber to a brake device via the hydraulic hose H. Thus, thepiston 22, the operating member 24, the hydraulic reservoir 26 and thecylinder bore 44 constitute a hydraulic brake unit.

In this first embodiment, a biasing element 53 is provided for biasingthe piston 22 to a rest position in which the hydraulic cylinder chamberhas the largest volume. In the first illustrated embodiment, as seen inFIG. 4, the biasing element 53 is a pair of coil torsion springs 53 a(return springs).

As illustrated in FIG. 4, the operating member 24 includes a lever 54that is pivotally mounted relative to the base member 20. The lever 54is directly pivotally mounted to the base member 20 by a pivot pin 56that defines a pivot axis P1. The lever 54 is an elongated operating(brake) lever that is operatively coupled to the piston 22 forperforming a bicycle braking operation. The lever 54 is biased to a restposition with respect to the base member 20 by a biasing element 58. Theoperating member 24 further includes an actuation cam 60 thatoperatively connects the piston 22 to the lever 54. The biasing element58 is operatively coupled between the lever 54 and the actuation cam 60to bias the lever 54 and the actuation cam 60 in opposite directionsabout the pivot axis P1. In this way, the lever 54 is biasing againstthe base member 20 to establish a rest position of the operating member24, and the actuation cam 60 biased into engagement with a pair ofrollers 62 on a connecting rod 64 that is attached to the piston 22. Theterm “rest position” as used herein refers to a state in which the part(e.g., the operating member 24) remains stationary without the need of auser holding the part in that state corresponding to the rest position.Thus, the lever 54 moves relative to the base member 20 from the restposition along a brake operating path BA (FIG. 3) to a braking positionfor performing a braking operation of a brake device (not shown).

In the first embodiment, the lever 54 is provided with a pair ofgearshift operating parts 66 and 68 for performing gearshiftingoperations of a gear changing device (not shown). The gearshiftoperating parts 66 and 68 are electrically connected to the shift unit30 that is mounted within a recess in the base member 20. The gearshiftoperating parts 66 and 68 are pivotally mounted on the lever 54 to pivotabout a pivot axis P2. The shift unit 30 and the gearshift operatingparts 66 and 68 are constructed as shown in U.S. Patent ApplicationPublication No. 2009/0031841 A1 (assigned to Shimano, Inc.). It will beapparent to those skilled in the bicycle field that the shift unit 30and the gearshift operating parts 66 and 68 that are not limited to theillustrated structure and arrangement, but rather other suitablestructures and arrangements can be used as needed and/or desired. Here,the shift unit 30 is an electrical shift unit that includes amicrocomputer with a processor and a pair of electrical switches (e.g.press type contact switches or a normally open contactless switches).Alternatively, the processor of the shift unit 30 can be located in thebase member 20 or remotely located from the bicycle hydraulic operatingdevice 12 if needed and/or desired. Since various electrical shiftingsystems such as the one illustrated herein are known in the bicyclefield, shift unit 30 and the gearshift operating parts 66 and 68 willnot be discussed herein for the sake of brevity.

As seen in FIGS. 3 to 6, the hydraulic reservoir 26 is a separate partthat is integrally fixed to the base member 20. The hydraulic reservoir26 provides hydraulic fluid to the hydraulic cylinder chamber that isdefined by the space formed between the piston 22 and the internalsurface of the cylinder bore 44 in the base member 20. The hydraulicreservoir 26 is provided so that the necessary amount of hydraulic fluidcan be injected from the hydraulic reservoir 26 even if the frictionmaterial (for example, a brake pad) of the braking device becomes worn.In particular, the amount of hydraulic fluid needed in the hydrauliccylinder chamber increase as the friction material of the braking devicebecomes worn. Also, the hydraulic reservoir 26 prevents inconsistenciesin the pressure being applied to the braking device due to swelling andcontraction caused by changes in the temperature of the hydraulic fluid.Hydraulic pressure is generated through the movement of the piston 22 inresponse to operation of the lever 54.

Basically, the hydraulic reservoir 26 includes a hydraulic reservoirtank 70, a reservoir lid 72 and a diaphragm 74. The diaphragm 74 that isat least partially disposed inside the hydraulic reservoir tank 70.While the hydraulic reservoir tank 70 is illustrated as being separatefrom the base member 20, it will be apparent from this disclosure thatthe base member 20 can be integrally molded as one-piece unitary memberwith respect to the base member 20. The diaphragm 74 divides thehydraulic reservoir tank 70 into an air chamber C1 and a hydraulic fluidchamber C2. The hydraulic reservoir 26 at least partially forms thepommel portion 34.

The hydraulic reservoir tank 70 is made of a suitable rigid, hardmaterial such as a hard plastic material (e.g., resin), a fiberreinforced plastic material (e.g., resin), a metallic material, etc.However, preferably, the hydraulic reservoir tank 70 and the base member20 are made of a resin material. In this way, the hydraulic reservoirtank 70 is bonded to the base member 20 by using a suitable adhesiveand/or heat welding. In the first embodiment, preferably, the hydraulicreservoir tank 70 is fixed to the base member 20 by a fastenerless joint76. The term “fastenerless joint” as used herein means a joint betweentwo parts that is accomplished without using mechanical fasteners, suchas but not limited to rivets or bolts, screws. The type of fastenerlessjoint will partly depend on the materials of the hydraulic reservoirtank 70 and the base member 20. Some examples of fastenerless jointsinclude adhesive bonding, pressure-sensitive tapes, soldering,ultrasonic plastic welding, ultrasonic metal welding, plastic to plasticfusing, metal to metal arc welding, and laser welding. Thus, thefastenerless joint 76 can be made without a binder material, such as anadhesive or a filler, or can be made with such a binder material.

In the first embodiment, a portion of the base member 20 is formed of atransparent or translucent material in the area of the hydraulic fluidflow path. In this way, a user can easily inspect both the cylinder bore44 and the fluid passage 52. In the first embodiment, the portion of thebase member 20 that is covered by the cover 42 is made of a transparentor translucent material, while the portion of the base member 20 that isnot covered by the cover 42 is made of a transparent or translucentmaterial. Thus, with the the cover 42 fully installed on the base memberand the hydraulic reservoir 26, the portion of the base member 20 thatis not covered by the cover 42 is made of an opaque material. Also inthe first embodiment, the hydraulic reservoir 26 entirely is formed of atransparent or translucent material. In other words, the hydraulicreservoir tank 70, the reservoir lid 72 and the diaphragm 72 are allentirely made of a transparent or translucent material. In this way, auser can easily inspect inside the hydraulic reservoir 26. However, itis not necessary for the hydraulic reservoir tank 70, the reservoir lid72 and the diaphragm 72 to be entirely made of a transparent ortranslucent material. At least part of one of the base member 20 and thehydraulic reservoir 26 includes a fluid inspection portion makingvisually perceptible therethrough at least a portion of a hydraulicfluid flow path that includes the hydraulic reservoir 26, the cylinderbore 44 and the fluid passage 52. Preferably, the fluid inspectionportion is disposed on at least one of the hydraulic reservoir tank 70,the reservoir lid 72 and the diaphragm 72.

Referring to FIGS. 4 and 5, the hydraulic reservoir tank 70 is fluidlyconnected to the cylinder bore 44. In particular, the fluid passage 52fluidly connects hydraulic reservoir tank 70 to the cylinder bore 44.The hydraulic reservoir tank 70 has a tank opening 70 a and a tank body70 b. The reservoir lid 72 closes the tank opening 70 a of the hydraulicreservoir tank 70. The bicycle hydraulic operating device 12 preferablyfurther comprises a bleed port 78 fluidly connected to the hydraulicfluid flow path. The bleed port 78 is preferably disposed on thehydraulic reservoir 26 as in the first embodiment. In particular, asseen in FIG. 3, the hydraulic reservoir tank 70 includes the bleed port78 for bleeding air from the hydraulic fluid chamber C2. The bleed port78 can also be used for adding hydraulic fluid to the hydraulic fluidchamber C2 instead of removing the reservoir lid 72. The bleed port 78is closed by a bleed screw 80. Thus, the bleed port 78 has an internalthread for screwing the bleed screw 80 into the bleed port 78.

In the first embodiment, as seen in FIG. 6, the tank opening 70 a isrectangularly shaped. Specifically, the tank opening 70 a is stepped forreceiving a portion of the diaphragm 74 as discussed below. The upperedge of the hydraulic reservoir tank 70 has an annular groove 70 c thatreceives a portion of the diaphragm 74. The hydraulic reservoir tank 70has a non-uniformed shape in which the tank opening 70 a has a differentcross sectional profile from a cross sectional profile of the tank body70 b. In this way, the tank body 70 b of the hydraulic reservoir tank 70can be made larger than the tank opening 70 a. In the first embodiment,preferably, the hydraulic reservoir tank 70 has an open bottom definedby a peripheral edge 70 d that is fixed to the base member 20 by thefastenerless joint.

Here, in the first embodiment, the hydraulic reservoir tank 70 is freeof a bottom wall and is free of hidden surfaces. In other words, thehydraulic reservoir tank 70 has only non-hidden surfaces. In this way,the tank body 70 b can be integrally molded as one-piece, unitary memberusing straight, draw-type molds that have no undercut (hidden) surfaces,(i.e., with only non-hidden surfaces). The phrase “hidden surface(s)” asused in this disclosure refers to a surface or surfaces of a molded partwhich does not directly face a straight draw-type mold. In other words,a hidden surface or an undercut surface is a surface which faces anothersurface of the molded part such that a pair of straight draw-type moldscannot be used to form the hidden surface. The phrase “draw-typeinjection molding” as used herein refers to the use of an injection moldcomprised of two halves which are separated from each other by movingeach half of the mold apart from the other along a straight line tocreate an injection molded part without the use of mold sliders tocreate hidden or undercut surfaces.

Referring to FIG. 5, the tank opening 70 a defines an opening crosssectional area A1. The opening cross sectional area A1 of the tankopening 70 a is defined as a minimum area in the case where the tankopening 70 a has a non-uniform shape as is the case of the firstembodiment. The hydraulic reservoir tank 70 defines a tank crosssectional area A2 that is parallel to the opening cross sectional areaA1. The tank cross sectional area A2 of the tank body 70 b is defined asa minimum area in the case where the tank body 70 b has a non-uniformshape as is the case of the first embodiment. The opening crosssectional area A2 of the tank opening 70 a is smaller than the tankcross sectional area A1 of the hydraulic reservoir tank 70.

The diaphragm 74 is a flexible, resilient member made of a suitablematerial such as a rubber material. The diaphragm 74 is a unitary,one-piece member. Preferably, as in the first embodiment, the diaphragm74 is a bottle shaped member including a neck portion 74 a and a bodyportion 74 b which is larger than the neck portion 74 a. Preferably, thehydraulic reservoir tank 70 has the bleed port 78 opening adjacent to aneck area of the hydraulic fluid chamber C2 that is defined by the neckportion 74 a of the diaphragm 74.

As seen in FIG. 4, the body portion 74 b of the diaphragm 74 has a crosssectional area A3 that is parallel to the opening cross sectional areaA1. The cross sectional area A3 of the body portion 74 b of thediaphragm 74 is defined as a maximum area in the case where the bodyportion 74 b of the diaphragm 74 has a non-uniform shape as is the caseof the first embodiment. Also, the cross sectional area A3 of the bodyportion 74 b of the diaphragm 74 is larger than the opening crosssectional area A1 of the tank opening 70 a. The neck portion 74 a has adiaphragm opening 74 c which is arranged opposite to the body portion 74b. The neck portion 74 a is fixed on the tank opening 70 a. Inparticular, the neck portion 74 a has a peripheral mounting flange 74 cthat extends annually outwards. The annular groove 70 c in the upperedge of the hydraulic reservoir tank 70 receives the peripheral mountingflange 74 c of the diaphragm 74. The peripheral mounting flange 74 c ofthe diaphragm 74 is sandwiched between the reservoir lid 72 and theupper edge of the hydraulic reservoir tank 70.

The reservoir lid 72 is frictionally retained in the tank opening 70 aof the hydraulic reservoir tank 70 by slightly compressing the diaphragm74. As a result, a seal is created by the diaphragm 74 between thehydraulic reservoir tank 70 and the reservoir lid 72. The reservoir lid72 has an air passageway 72 a connecting the air chamber C1 to outsideof the base member 20. Preferably, the reservoir lid 72 is made of aresin material.

Referring now to FIG. 7, a bicycle hydraulic operating device 212 isillustrated in accordance with a second embodiment. The bicyclehydraulic operating device 12 basically comprises a base member 220, apiston 222, an operating member 224 and a hydraulic reservoir 226. Thebicycle hydraulic operating device 12 further comprises a handlebarmounting structure 228 that is disposed on the base member 220.Preferably, the bicycle hydraulic operating device 212 further comprisesa shifting unit 230 that is disposed on the base member 220. Also thebicycle hydraulic operating device 212 further comprises a cover 242.The hydraulic reservoir 226 is fluidly connected to a cylinder bore 244that is formed in the base member 220. The hydraulic reservoir 226 isidentical to the hydraulic reservoir 26. The cylinder bore 244 has anoutlet port 248 that is fluidly connected to the hose H. Also, a fluidpassage 252 extends between the hydraulic reservoir 226 and the cylinderbore 244 for supplying hydraulic fluid from the hydraulic reservoir 226to the cylinder bore 244. Thus, the hydraulic reservoir 226 includes ahydraulic reservoir tank 270, a reservoir lid 272 and a diaphragm 274.

The shifting unit 230 is a mechanical shifting unit that basically hasthe same structure and operates in the same way as the so called holdingmechanism that is disclosed in U.S. Pat. No. 7,779,718. However, theshifting unit 230 has been configured to be supported by the base member220 and operated by a control cable (e.g., Bowman cable). In otherwords, the shifting unit 230 is operated by a control lever 231 in thesame manner as the control lever for the so called holding mechanismthat is disclosed in U.S. Pat. No. 7,779,718. Since the structure andoperations of the shifting unit 230 are well known to those skilled inthe bicycle field, the structure and operations of the shifting unit 230will not be discussed in detail herein.

In the third embodiment, the piston 222 and the operating member 224 areconfigured as a piston push-type hydraulic actuator. Here, a biasingelement 253 is provided for biasing the piston 22 to a rest position inwhich the hydraulic cylinder chamber has the largest volume. In thethird embodiment, the biasing element 253 is a compression spring. Thebiasing element 253 is also used to biasing the operating member 224 toa rest position. In particular, the piston 222 is operatively coupled tothe operating member 224 by a connecting rod 264. Thus, the biasingforce of the biasing element 253 is transmitted to the operating member224 via the connecting rod 264. Preferably, the connecting rod 264 has afirst end pivotally coupled to the piston 222 and a second end pivotallycoupled to the operating member 224.

Here, the operating member 224 is pivotally mounted on the base member220 to pivot about the pivot axis P1 such that operation of theoperating member 224 from the rest position to an operated positionabout the pivot axis P1 causes the piston 222 to be pushed inside of thecylinder bore 244. Thus, hydraulic fluid is forced out of the cylinderbore 244 via the outlet port 248 to the brake device (not shown). Sincethe piston push-type hydraulic actuators are known in the bicycle field,the piston push-type hydraulic actuator of the bicycle hydraulicoperating device 212 will not be discussed or illustrated in detailherein.

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts unless otherwise stated.

As used herein, the following directional terms “frame facing side”,“non-frame facing side”, “forward”, “rearward”, “front”, “rear”, “up”,“down”, “above”, “below”, “upward”, “downward”, “top”, “bottom”, “side”,“vertical”, “horizontal”, “perpendicular” and “transverse” as well asany other similar directional terms refer to those directions of abicycle in an upright, riding position and equipped with the bicyclehydraulic operating device. Accordingly, these directional terms, asutilized to describe the bicycle hydraulic operating device should beinterpreted relative to a bicycle in an upright riding position on ahorizontal surface and that is equipped with the bicycle hydraulicoperating device. The terms “left” and “right” are used to indicate the“right” when referencing from the right side as viewed from the rear ofthe bicycle, and the “left” when referencing from the left side asviewed from the rear of the bicycle.

Also it will be understood that although the terms “first” and “second”may be used herein to describe various components these componentsshould not be limited by these terms. These terms are only used todistinguish one component from another. Thus, for example, a firstcomponent discussed above could be termed a second component and viceversa without departing from the teachings of the present invention. Theterm “attached” or “attaching”, as used herein, encompassesconfigurations in which an element is directly secured to anotherelement by affixing the element directly to the other element;configurations in which the element is indirectly secured to the otherelement by affixing the element to the intermediate member(s) which inturn are affixed to the other element; and configurations in which oneelement is integral with another element, i.e. one element isessentially part of the other element. This definition also applies towords of similar meaning; for example, “joined”, “connected”, “coupled”,“mounted”, “bonded”, “fixed” and their derivatives. Finally, terms ofdegree such as “substantially”, “about” and “approximately” as usedherein mean an amount of deviation of the modified term such that theend result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, unless specifically stated otherwise,the size, shape, location or orientation of the various components canbe changed as needed and/or desired so long as the changes do notsubstantially affect their intended function. Unless specifically statedotherwise, components that are shown directly connected or contactingeach other can have intermediate structures disposed between them solong as the changes do not substantially affect their intended function.The functions of one element can be performed by two, and vice versaunless specifically stated otherwise. The structures and functions ofone embodiment can be adopted in another embodiment. It is not necessaryfor all advantages to be present in a particular embodiment at the sametime. Every feature which is unique from the prior art, alone or incombination with other features, also should be considered a separatedescription of further inventions by the applicant, including thestructural and/or functional concepts embodied by such feature(s). Thus,the foregoing descriptions of the embodiments according to the presentinvention are provided for illustration only, and not for the purpose oflimiting the invention as defined by the appended claims and theirequivalents.

What is claimed is:
 1. A bicycle hydraulic operating device comprising:a base member having a cylinder bore; a piston movably disposed in thecylinder bore; an operating member coupled to the piston to move thepiston within the cylinder bore; and a hydraulic reservoir provided onthe base member and fluidly connected to the cylinder bore by a fluidpassage, at least part of one of the base member and the hydraulicreservoir includes a fluid inspection portion making visuallyperceptible therethrough at least a portion of a hydraulic fluid flowpath that includes the hydraulic reservoir, the cylinder bore and thefluid passage.
 2. The bicycle hydraulic operating device according toclaim 1, wherein the hydraulic reservoir includes a hydraulic reservoirtank provided on the base member, a reservoir lid closing a tank openingof the hydraulic reservoir tank and a diaphragm that is at leastpartially disposed inside the hydraulic reservoir tank.
 3. The bicyclehydraulic operating device according to claim 2, wherein the hydraulicreservoir tank and the base member are made of a resin material.
 4. Thebicycle hydraulic operating device according to claim 3, wherein thereservoir lid is made of a resin material.
 5. The bicycle hydraulicoperating device according to claim 2, wherein the fluid inspectionportion is disposed on at least one of the hydraulic reservoir tank, thereservoir lid and the diaphragm.
 6. The bicycle hydraulic operatingdevice according to claim 2, wherein the hydraulic reservoir tank isbonded to the base member.
 7. The bicycle hydraulic operating deviceaccording to claim 2, wherein the hydraulic reservoir tank is fixed tothe base member by a fastenerless joint.
 8. The bicycle hydraulicoperating device according to claim 1, further comprising a bleed portfluidly connected to the hydraulic fluid flow path.
 9. The bicyclehydraulic operating device according to claim 8, wherein the bleed portis disposed on the hydraulic reservoir.
 10. The bicycle hydraulicoperating device according to claim 1, further comprising a handlebarmounting structure disposed on the base member.
 11. The bicyclehydraulic operating device according to claim 1, wherein the operatingmember includes a lever pivotally mounted relative to the base member.12. The bicycle hydraulic operating device according to claim 1, whereinthe base member is configured to be gripped by a user.
 13. The bicyclehydraulic operating device according to claim 12, wherein the basemember includes a handlebar receiving recess arranged at a first endportion and a pommel portion arranged at a second end portion oppositeto the first end portion.
 14. The bicycle hydraulic operating deviceaccording to claim 13, wherein the hydraulic reservoir at leastpartially forms the pommel portion.
 15. The bicycle hydraulic operatingdevice according to claim 1, further comprising a shifting unit disposedon one of the base member and the operating member.
 16. The bicyclehydraulic operating device according to claim 1, further comprising acover removably and reattachably disposed on the base member and atleast overlying the fluid inspection portion.
 17. The bicycle hydraulicoperating device according to claim 16, wherein the cover is configuredto at least visually cover the fluid inspection portion.
 18. The bicyclehydraulic operating device according to claim 16, wherein the cover ismade of a rubber material.